[Samba] Prevent smbpasswd lan manager field change

[Jansen Robert]

Dear all,

We recently upgraded an old samba 3.0.10 to 3.4.6 due to broken quota when
moving from Veritas to NFS mounts from a Cellera EMC.

Anyway,

Our samba passwd backend is a smbpasswd file.
This file is generated from a database.

Recently we see that some PC clients manage to change the LANMAN field in
the smbpasswd file.

e.g.

userabc:108:364CBAE2BB8E8B05C2265B23734E0DAC:105F5CD7D6E85B97EDC2677D47C6B173:[U
         ]:LCT-4977B700:

get changed to

userabc:108:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX:105F5CD7D6E85B97EDC2677D47C6B173:[U
         ]:LCT-4977B700:

Users do NOT have access to the smbpasswd binary, so it's via a client
request
(verified this via a Win 7 client trying the change his Samba passwd)

Can anyone shed some light on why this happens in the 3.4.6 version ?
We actually do not want this to happen as the smbpasswd file is getting
out of sync with our database.

As far as I understand all the smb.conf options with their default setting
should prevent changes in the smbpasswd file.


Here's our smb.conf:

# Global parameters
[global]
        server string = ACME Samba
        log level = 01
        log file = /tmp/SAMBA/logs/log.%m
        max log size = 200
        name resolve order = lmhosts host wins bcast
        socket options = TCP_NODELAY SO_KEEPALIVE
        load printers = No
        dns proxy = No
        ldap ssl = no
        create mask = 0600
        directory mask = 0700
        hosts allow = <obfuscated>
        delete readonly = Yes


        passdb backend = smbpasswd


[homes]
        comment = Home Directories
        read only = No
        map system = Yes
        map hidden = No
        browseable = No
        dos filemode = Yes

[printers]
        comment = All Printers
        path = /usr/spool/samba
        printable = Yes
        browseable = No


Thanks in advance

Regards,




--------------------------
Brussels University
Pleinlaan 2
Computer Center VUB/ULB (VUBnet)
Ing. Robert Jansen
B-1050 Brussels
Belgium (Europe)


email: rjansen at vub.ac.be
Tel:  +32-2-650.36.94
Secr: +32-2-650.37.38
Fax:  +32-2-650.37.40
--------------------------